Internal-combustion engine



INTERNAL COMBUSTION ENGINE Filed June 13, 1924 Char/es K/I/g/if ATTOR Patented Mar. 11, 1930 UNITED STATES PATENT OFFICE CHARLES Y. KNIGHT, OF PASADENA, CALIFORNIA, ASSIGNOR TO KNIGHT & KILBOURNE DEVELOPMENT 00., OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS INTERNAL-COMBUSTION ENGINE Application filed June 13,

My invention relates to improvements in internal combustion engines and has to do, more particularly, with improvements in the construction of pistons for such engines.

One of the objectionable features of the usual internal combustion engine is the presence of a distinct noise or knock, when the engine is in operation, due to what is known as piston slap. flhere is usually considerable clearance between the piston and the wall of the cylinder in which it reciprocates. When the piston is ascending on the compression stroke, the forces acting on the piston, due to the angularity of the connecting rod, cause the piston to become slightly eccentric in the cylinder, engaging one side thereof rather closely while there is a considerable clearance between the opposite side of the piston and the cylinder Wall. When the piston reaches top-dead-center and begins to descend on the power stroke, the force exerted by the explosion tends to move the piston into engagement with ,the opposite wall of the cylinder. This movement of the piston from one side of the cylinder to he other, if unrestrained, produces a distinct metallic noise or knock known as piston slap and the main objectof my present invention is to provide a construction by means of which piston slap is eliminated.

A further object of my present invention is to provide a construction which holds the piston steady in the cylinder preventing it from rocking or slapping from one side to the other.

A further object of my inventionv is to provide a construction which holds the piston steady in correct position to receive the impact of the firing charge and to prevent the piston from traveling across the clearance under the impact of such charge.

A leading object of my invention is to provide an internal combustion engine which is much less nois and has less vibration than engines heretofbre produced.

In my copending applications, Serial No. 616,928, filed Feb. 5, 1923, means for holding piston against vibration at ends of stroke, Serial No. 644,103, filed June 8, 1923, piston and rod connection, and Serial No.

I924. Serial No. 719,722.

644,104, filed June 8, 1923, engine piston and piston rod assembly, Ihave disclosed certain constructions for accomplishing the general purposes of my present invention, and one object of the present invention is to provide a construction which is cheaper to manufacture and easier to assemble than said constructions. In certain respects, my present invention is an improvement upon the invention disclosed and claimed in my pending application, Serial No. 616,928.

One object of my present invention is to provide means for maintaining a pool of suitable liquid, such as lubricating oil, in position to act as a cushion restraining transverse motion of the piston in the cylinder.

A further object of my present invention is to provide a piston construction which is .substantially noiseless and 'vibrationless and in which all wear is automatically taken up so that noadjustment for wear is required.

Another object of my present invention is to provide means for employing oil to preserve the fit between the piston and the cylinder in which it reciprocates.

Further objects, and objects relating to details and economies of construction and operation, will definitely appear from the detailed. description to follow. In one instance, I accomplish the objects of my invention by the devices and means set forth in the following specification. My invention is clearly defined and pointed out in the appended claims. A structure constituting one embodiment of my invention is illustrated in the accompanying drawings, forming a part of this specification, in which:

Fig. 1 is a fragmentary sectional view .through the cylinder and piston of an internal combustion engine embodyingmy in-,

In general, I accomplish the objects of my invention by providing an element carried by the piston and maintained against: the wall of the cylinder, within which the piston works, by suitable fluid pressure so as to steady the piston in its reciprocatory movement within the cylinder and prevent it from traveling from one side of the cylinder to the other, as the direction in which forces are exerted on said piston varies. I propose to provide a sort of dash pot construction which is carried by the piston and which may be connected with the lubricating system of the internal combustion engine 'so that the lubricating oil is supplied to said dash pot at regular intervals to maintain one element thereof pressed into contact with the cylinder wall. I propose to provide connections between the lubricating system and this dash potconstruction of such a nature that lubrieating oil will be introduced into the dash pot when the piston is at or near the top of its stroke and so that said dash pot will be sealed at other times to prevent the lubricating oil or other fluid being forced or displaced therefrom. I propose, therefore, to provide means for maintaining a pool of a suitable liquid in position to serve as a cushion restraining transverse movement of the piston within the cylinder. I find it very convenient to use lubricating oil for this liquid inasmuch as this permits me to take the liquid necessary to form a pool from the lubricating system of the engine.

Referring to the numbered parts of the accompanying drawing, which illustrate one embodiment of my invention, more or less diagrammatically, I have shown a cylinder, 10, of an internal combustion engine within which the piston, 11, reciprocates. The piston, 11, is provided with the usual piston rings, 12, which engage the cylinder wall yieldingly and prevent passage of gasoline or lubricant from one side of the piston to the other. A wrist pin, 13, is carried in suitable trunnions, 34, formed in the piston, 11, and the upper end of the connecting rod, 14, is journaled on this wrist pin in the usual manner. The lower end of said connecting rod is journaled on the arm, 15, of the crank shaft, 16, in accordance with the usual practice.

An opening is formed in the side wall of the piston skirt and the piston is provided with a cylindrical wall, 17, extending inwardly of the piston from the edge of said opening. The axis of this cylindrical wall, 17, preferably extends at right angles to and intersects the axis of the wrist pin, 14, as appears very clearly in Fig. 1 of the drawing. A plunger, 18, having a cylindrical skirt, 19, is slidably mounted in the cylindrical chamber formed by said wall, 17, the outer end of said plunger, 18, being curved so as to form part of a cylinder corresponding to the cylindrical wall of the piston, 11. A member, 20, fits within the cylindrical recess formed in the danger, 18, by said wall, 19, said member, 20, having a cylindrical wall, 21, engag ing the wall, 19, of the plunger, 18. The member 20, is provided with a central, axially-extending stem, 22, having its inner end curved, at 23, to lit the curved upper end of the connecting rod, 14, as shown in Fig. 1. This stem, 22, is provided with a recess, 2 in which a spring, 26, is seated, said spring being interposed between the bottom of the recess, 24, and the inner wall of the plunger, 18, and acting to force said plunger outward- 1y away from the wrist pin, 13.

The crank shaft, 16, is provided with the usual passage, 27, through which lubricating oil may flow as in the usual engine construction. Such oil may be supplied to said passage under pressure developed by any suitable oil pump driven by the engine. The crank arm, 15, has a radial passage, 28, connecting with the passage, 27, and the connecting rod, 14, is provided with a longitudinal passage, 29. The wrist pin, 13, is provided with a central passage, 31, adapted to receive lubricating oil and with radial passages, 30 and 32, connecting with said central passage. The upper end of the connecting rod has a radial passage, 33, as shown in Fig. 1. It will be observed that, when the parts are in the position shown in Fig. 1, the passages, 28, 29, and 30, are in line with each other so that lubricating oil from passage, 27, may flow through passages, 28, 29 and 30, to the passage 31, in the wrist pin. At the same time passages, 32 and 33, are in line with each other and the outer end of the passage. 33, is just below the inner end of the passage, 25. In Fig. l, the parts are shown at top dead center and, as the piston descends on its power stroke, the change in angularity of the connecting rod, 14, as the crank shaft rotates in the direction of the arrow (Fig. 1) will bring the passages, and 25, into line with each other so that lubricating oil may flow therethrough into the space between the member, 20, and the plunger, 18, if such space is not already filled to its capacity. As the piston descends still further, the passages, 29 and 28, will move out of alignment with each other, as indicated by dotted lines in Fig. 1, so that a supply of lubricant through the passage, 29, from the lubricating system is shut off.

It will be observed that the passage, 25, is located slightly above the axis of the plunger, 18, and slightly above the axis of passage, 33, and the result is that communication through passages, 25 and 33, will be open during substantially the entire downstroke of the piston and closed during substantially the entire upstroke of the piston.

The operation of this construction should be quite apparent from the description which I have heretofore given. The spring, 26, tends to project the plun er, 18, against the cylinder wall away from t e member, 20, and the pool of lubricating oil which is maintained sealed in the space between the plunger, 18, and the member, 20, assists the spring in holding the plunger projected. As the piston passes the top dead center and the explosion takes place, the impact of the exploding gases upon the piston produces a force, due to the angularity of the connecting rod, which tends to throw the piston against the side of the cylinder opposite the plunger, 18. While the piston is held against this side of the cylinder, the spring, 26, forces the plunger, 18, as far in the opposite direction as possible so that it is in contact with the opposite wall of the cylinder. When the piston moves upward in the cylinder on the compression stroke, the pressure due to the compression of the charge combined with the force exerted on the piston through the crank shaft and connecting rod, exerts a force acting to move the piston transversely of the cylinder but such movement is efi'ectively resisted by the engagement of the plunger, 18, with the cylinder wall and the pool of 'oil maintained in the space between the plunger, 18, and the member, 20, acts to re strain movement of the plunger and conse quently transverse movement of the piston. The connections between this space and the lubricating system are such that this pool of oil is renewed at predetermined points in the revolution of the crank shaft. As the piston starts to descend after the explosion, and as it is held thereby against the right hand cylinder wall, the connection between the passage, 33, and the passage, 25, is open so that lubricating oil may be drawn or forced from the passage, 27, through the connecting rod passage, 29, and into the space be-, tween the plunger, 18, and the member, 20. At other points in the revolution of the crank shaft, this pool of oil is sealed both because of thefact that the passage, 28, is out of line with the passage, 29,and the passage, 33, is out of line with the passage, 25. Thus -when the piston is pressed against the right hand side of the cylinder as shown in Fig. 1, and the plunger 18 is at its extreme outward position with respect to the cylinder, the passage through the connecting rod is open and oil is free to flow into the space between the plunger 18 and the member 20,

but when the piston tends to move transversely in the cylinder thereby moving the plunger inwardly, thepassage through the connecting rod is closed, preventing the oil from escaping and the plunger from moving inwardly.

It will be observed that I have provided of the piston transversel of the cylinder,

which causes piston slap, is eliminated. The maintenance of a pool of oil behind the plunger, 18, serves to resist and restrain such transverse movement of the piston. This forms a sort of dash pot construction to which liquid is supplied regularly, as needed, from the lubricating system. Any liquid escaping through the joints between these moving parts may also serve to lubricate the wrist pin bearings and the cylinder wall. I have shown a piston reciprocating within a fixed cylinder but it is to be understood that my invention is also applicable to engines in which the piston reciprocates within a movable cylinder or sleeve, as, for instance, in the Knight type sleeve valve motor.

I- am aware that the particular embodiment of my invention which has been disclosed herein may be altered considerably without departing from the spirit thereof, and therefore I claim my invention broadly as indicated by the appended claims.

Having thus described my invention, what I claim as new and useful and desired to secure by Letters Patent is:

1. In an internal combustion engine, the combination with a cylinder and a piston mounted for reciprocation therein, of an extensible member slidably mounted in the side of said piston, and independent of said piston, said piston acting solely as a guide for said member; means to draw a fluid into said member when said piston is held against the side of said cylinder opposite to said member by external forces; and means to prevent the fluid from escaping during the remainder of the stroke.

2. In an internal combustion engine, the combination with a cylinder, a piston mounted for reciprocation therein and a connecting rod connected to said piston; of an extensible member independent of said piston slidably mounted in the side thereof, and adapted to bear against the wall of said cylinder; an oil passage in said connecting rod communicating with the interior of said member; means to extend said member when said piston is held against the side of said cylinder opposite to said plunger by external forces whereby fluid is drawn into the interior of said member through said oil passage; and means to close off said oil passage during the remainder of the stroke to prevent the escape of the oil.

3. In an internal combustion engine, the combination with a cylinder, a piston mounted for reciprocation in said cylinder and a connecting rod pivotall connected to said piston; of a plunger sli ably mounted in the side of said piston, and ada ted to bear against the wall of said cylin er; means to a very simple and cheap construction byconnect said plunger with the upper end of means of which the piston is maintained steady within the cylinder and the movement said connecting rod and to automatically vary said connecting means to take up wear in the connection between said connecting rod and piston.

4. In an internal combustion engine, the combination with a cylinder, a piston mount- 5 ed for reciprocation therein and a connecting rod pivotally connected to said piston; of a plunger slidably mounted in the side of said piston and adapted to bear against the side wall of said cylinder; a base member bearing against the upper end of said connecting rod; means to constantly urge said plunger and base member apart; and means to admit a fluid to the space between said members.

5. In an internal combustion engine, the combination with a cylinder, a piston mounted for reciprocation therein and a connecting rod pivotally connected to said piston of noncompressible means independent of said piston to hold the upper end of the connecting rod against lateral movement with respect to the walls of the cylinder, regardless of the clearance between the iston and the cylinder walls, or the play in t 1e connection between the piston and the connecting rod.

6. In an internal combustion engine, the combination with 'a cylinder, a piston reciprocating therein, and a connecting rod connected to said piston, of a plunger carried by said piston and movable through the side wall thereof into engagement with the cylinder wall, said plunger having a cup shaped recess in the inner end thereof, a base member fitting in said recess and provided with a portion engaging the end of the connecting rod, and means for admittin lubricating oil to the space between said pIunger and the base member. 7

7. In an internal combustion engine, the combination with a cylinder, a piston and a connecting rod connected to said piston, of a plunger movable through the side wall of said piston and having a cup shaped recess in its inner end, a base member fitting in said recess and provided with a stem fitting the end of said connecting rod and engaging the same,

lubricating oil passages in said connecting rod, and a passage in said stem leading to the space between said base member and plunger, the end of said last mentioned passage being adapted to communicate with one of the passages in said connecting rod at certain portions of the piston stroke.

8. In an internal combustion engine, the combination with a cylinder, a piston mounted for reciprocation in said cylinder and a connectin rod pivotally connected to said piston; 0 means independent of said piston comprising a fluid cushion for maintaining said piston and said connecting rod at their extreme limit toward one side of the cylinder during the inward stroke thereof; and means to replenish said maintaining means during the outward stroke of the piston.

9. In an internal combustion engine, the combination of a cylinder, a piston reciproeating therein, and a connecting rod, the skirt of said piston having an opening therein and being provided with a cylindrical flange extending inwardly from the edge of said opening, a plunger slidably mounted in said cylindrical flange and engaging the wall of said cylinder, said plunger having a cup shaped recess formed in its inner end, a base member mounted in said recess and having a stem extending into engagement with the upper end of said connecting rod, the end of said stem being formed to fit the end of said connecting rod, said stem being provided with a passage communicating with the space between said base member and plunger, and said connecting rod having passages communicating with the engine lubricating system whereby oil may be forced under pressure into said space during certain portions of the piston stroke and sealed within said space during other portions of the piston stroke.

In testimony whereof, I aflix my signature.

CHARLES Y. KNIGHT. 

